Ext.create('Ext.tab.Panel', {
             region: 'center', // a center region is ALWAYS required for border layout
             deferredRender: false,
             activeTab: 0,     // first tab initially active
             id:'mainContent',
             items: [{
                 title: '首页',
                 autoScroll: true,
                 html:"welcome to"
             }, {
                 title: 'close me',
                 autoScroll: true,
                 closable: true,
                 html:"xxx"
             }]
    	 })